Pre-fabricated stairway

ABSTRACT

A stairway including a plurality of components including stair supporting masts and stair units. The stair support masts and stair units are stored and shipped as components and assembled into a stairway at the building site.

I United States Patent 91 1 1 3,707,814 Seegers 1 Jan. 2, 1973 [54] PRE-FABRICATED STAIRWAY [56] References Cited [75] Inventor: Glen A. Seegers, Lombard, 111. UNITED STATES PATENTS [73] Assignee: American Stair Corporation, Mc- 3,052,332 9/1962 Mulitz ..52/l85 Cook, L 3,228,154 1/1966 Mulitz ..52/1s5 3,310,132 3/1967 Rolland ..52/185 X [22] Filed: June 16, 1971 Primary Examiner-Price C. Faw, Jr. [21] Appl' 153637 AttorneyRoy E. Petherbridge et a1.

52 U.S. cl ..52/185 ABSTRACT [5 Int. CL A tairway including a plurality of components inelud- Field Of Search; ing stair supporting masts and stair units. The stair 52/191, 79 support masts and stair units are stored and shipped as components and assembled into a stairway at the building site.

8 Claims, 7 Drawing Figures PAIENTEnJm ms 3.701814 -s nm 1 or 2 INVENTOR.

GLEN A. SEEGE-RS 3.707.814 sum 2 m2 INVENTOR GLEN A. SEEGERS PRE-FABRICATED STAIRWAY The present invention relates to prefabricated stairways and more particularly to prefabricated stairways of the type which are installed on the exterior wall of a building and subsequently enclosed by a stairwell.

There has been a trend in the construction field toward the use of modular type stair units for erection of the exterior type stair wells. The modular units are fabricated and assembled at a fabrication plant located remote from the building site. These units are constructed so as to be self supporting and to be capable of being stacked vertically. The modular units thus constructed at the fabrication site are transported by flat deck motor vehicles or the like to the building construction site.

After the units are received at the building site they are assembled one upon the other to provide the necessary exterior wall stairs. Thereafter, the stair well walls are constructed about the assembled stair units to complete the structure.

While this method of forming the stairwell has been satisfactory, it has disadvantages. The modular units are of generally cubic or parallelepiped configuration and are of such a mass that cranes must be used at both the fabrication site to place them on the motor vehicles and to erect them at the building site. Moreover, the preassembled modular stair units occupy a large volume so that only limitednumbers of stair units may be hauled at one time. Obviously these preerected or preassembled modules also occupy considerable storage space at both the prefabrication and building sites.

In various types of preassembled units it has also been necessary to build or construct the stairwell about one of the preassembled stair units before another stair unit could be positioned thereon. This type of assembly unduly delayed the construction of the stair well because of the unavailability or difficulty in scheduling the masons and the like.

By the present invention it is proposed to provide a stair way unit which overcomes the difficulties encountered heretofore while retaining substantially all of the advantages of such prior units.

It is another object of the invention to provide a prefabricated stairway unit which is of a construction comprising a plurality of components including knockdown supports and a preassembled stair unit which occupy a minimum of space to pennit the hauling of greater number of stair units per truck load than was possible heretofore.

. It is still another object to provide a prefabricated stairway unit which is constructed so as not to require the use of cranes to assemble the same at the construction site.

The foregoing object and others, which will be readily apparent from the appended drawings and following specifications, are accomplished generally by a stairway unit comprising a plurality of vertical masts connectable at the construction site and adapted to be mounted in spaced relationship to each other and having cross arms connected along the heights thereof at different levels. A prefabricated stair, separate from the masts are supported at the upper end and lower ends between the cross arms located at different levels to retain the stair units at the proper inclination. The stair units are disposed at opposite sides of the cross arms.

In the drawings:

FIG. 1 is a fragmentary perspective view of an assembled stairway embodying the principles of the present invention.

FIG. 2 is a side elevational view of the prefabricated stair unit used in the construction of the assembled stairway of FIG. 1.

FIGS. 3, 4 and 5 are front elevational views of the different masts used in the assembled stairway for supporting the stair units.

FIG. 6 is a perspective fragmentary view showing the manner-in which the masts are connected.

FIG. 7 is a fragmentary side elevational view of the assembled prefabricated stairway of the present invention.

Referring now to the drawings in particular FIGS. 1 and 7, there is shown an assembled stairway unit 10 embodying the structure of the present invention and shown employed for use with an outside stairwell of a multi-story building. As shown, the stairway unit is serving two stories of a building. The stairway unit or assembly 10 comprises generally a plurality of stair units 11a, 11b, and 110 and upright masts including a short base mast 12, a long base mast l3 and a plurality of T masts 14 which serve to maintain and support the stair units in the inclined position shown. The stairway assembly is mounted in a concrete platform which is level with the first floor. After construction or assembly of the stair unit or assembly 10, stairwell 15 is constructed thereabout and platforms or landings 16 are mounted therein as shown by means of channels 17 extending between and embedded in stairwell walls 18.

The units 11a, 11b and lie may be one of the well known type and comprise I generally two laterally spaced stringers 19 including stringer plates 20 cut to provide stair risers and tread support surfaces. The steps may be made from anyone of the well known and accepted materials such as steel, wood, concrete or the like.

The landings 16 may be made in any suitable manner as, for example, by corrugated base member on which there is applied a thickness of concrete. The concrete is usually applied after the stair units are installed so as to be at the desired level relative to the steps. The platforms 16 are supported at each end on the stair well side walls during erection thereof.

The stringers 19 and stringer plates 20 are preferably 4 made from sheet steel or the like. The stringers 19 at the upper and lower ends thereof are formed with rectangular projections 22 between which there extends vertically disposed straps 23 and 24 respectively. Fixed to the lower ends of the riser tread stringer is an angle iron 25 having a downwardly depending leg 26 which is horizontally and predeterrninately spaced from the associated vertical plate 24 for reasons as more fully to be explained hereinafter.

A horizontal plate 27 extends between the opposite outer stringers l9 and is disposed so that the lower surface thereof is horizontally aligned with the underside of the upper rectangular projection 22 and spaced from thevertical plate 23.

For supporting the stair units 11a, 11b, and 11c in inclined relationship there is provided the short base mast 12 for supporting the upper end of the stair unit the long base mast 13 for supporting the lower end of the unit 11a and the upper end of the stair unit 11b and a plurality of identical T masts 14, for supporting the remaining stair unit 11c and additional stair units as required to extend the full height of the building with which the stairway is associated. The short base mast l2 and the long base mast 13 are connectable to the T masts 14 which are also connectable so as to form a continuous vertical support at each end of the stairs units as more fully to be explained. As shown, the T masts 14 are each equal in height to the distance between the various floors above the ground level.

As shown in FIG. 5, the short base 12 includes a vertical post 29 which is made from tubular steel and preferably of rectangular cross-section. Fixed to the lower end of the vertical post 29 as by welding is a pair of horizontally disposed base channels 30-30 and fixed to the upper end thereof is a horizontal disposed stair unit support channel 31. Fixed in the bore at upper end of the tubular post 29 as by a force fit or welding is an alignment block 32 as shown in FIG. 6.

The long base mast 13 is of substantially the same structure as the short base mast 12 with the exception that the post 33 thereof is substantially twice the height of the post 29. The mast 13 includes a pair of horizontally disposed base channels 3434 and an upper stair unit support channel 35 and an alignment plug 36.

The T mast 14 are each of identical structure and include a rectangular post 37 across the upper end of which there is fixed a horizontally disposed stair unit support U-shaped channel 38. An alignment block 39 is fixed in the upper end of the post 37. The post 37 of the T mast is substantially equal to twice the distance between landings 15. The stair unit support channels 31, 35 and 38 are of sufficient length so as to provide ends projecting beyond the stair stringers to support the stair units 11 on the opposite walls of the stairwell when the latter is constructed about the assembled staircase.

The stair units 11a, b and c and as many as required and the masts 12, 13 and 14 are prefabricated at the fabrication facility as shown in FIGS. 2-5 and shipped as an unassembled stairway component to the site at which the building is being constructed. This makes it possible to transport a greater number of stair units and masts per truck load than has been possible heretofore with the prior assembled parallelepiped stair units. To assemble the stairway 10, the base channels 3030 and 34-34 of the associated short and long base masts l2 and 13 are embedded in a concrete footing which is leveled after erection of the stairs. The masts l2 and 13 are spaced so as to maintain and support the stair unit 11a at the desired angle of inclination. Thereafter, the stair unit is positioned on one side of the respective posts 29 and 33 with the vertical leg 26 of the angle iron 25 at the lower end of the stair unit 110 disposed inside of the vertical web of the base channel 34 and the outer vertical strap 24 engaging the leading edge of the upper horizontal leg of the channel 34. At the upper end the horizontal plate 27 is supported on the inner portion of the horizontal upper edge of the stair support channel 31 while the vertical strap 23 overlies the outer leading edge thereof. In this manner the stair unit 11 is captured and supported between the upper stair unit support channel 31 and the lower base channel 34. If desired the assembly stair unit Ila may be welded at the angle iron 25 and the strap 23.

To support the stair unit 11b and 11 a mast 14 may be inserted at its lower end into the alignment block 32 projecting upwardly from the short base mast post 29. The T mast post 37 is then fixed to the alignment block 32 as by means of a plug weld. It is to be noted that the stair unit supporting channel 35 on the mast 13 extends above the short base mast channel 31 the distance required to support the second stair unit 11b at the required inclination. The stair unit 11b is supported on and between the upper channel 34 the long base mast channel on the opposite side of the posts 29 and 33 from the first stair unit 1 la. The stair unit 1 lb is maintained in position in the same manner as described in connection with the stair unit 11a by means of the angle iron vertical leg 26 and the strap 24 at the lower end and the vertical strap 23 and horizontal plate 27 at the upper end which the associated channels 31 and 35 on the masts l2 and 13.

Thereafter, another T mast 13 is seated on the alignment block 36 and weld thereto to provide an additional length of stair support structure. The third stair unit is then fixed between the stair unit support channel 35 and the channel 38 on the T mast 14 previously fixed and supported in the same manner as described heretofore.

The erection of the stairway 10 is continued to accommodate each of the floors of the building in the same manner as heretofore described. While the erection of the stair has been described as assembling the masts to each other after erection of the individual stair units, it should be readily apparent that the masts may be assembled to accommodate the required number of floors before they are erected and mounted in the foundation. It should be noted that the com ponents comprising the stairway are not of such a mass that a crane is essential to erect the stairway.

To permit the stairs to be used as scaffolding during construction rails may be welded between the opposing posts as shown.

At any convenient time the stair well walls may be constructed about the erected stairway 10. At this time the platforms 15 may be constructed so that proper alignment is achieved between the floor level in the building structure proper at the base of the stair units. During construction of the walls the projecting ends of the channel masts are embedded therein to support the latter. If desired when the mast channels are thus supported, the vertical posts may be removed by breaking the weld or cut-off. Also, on the desire, the posts may be cut-off intermediate the lengths thereof to provide posts for the railings.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and, therefore, the invention is not limited to that shown in the drawings and described in the specifications but only as indicated in the appended claims.

What is claimed:

l. A prefabricated stairway having the components thereof designed so as to be storable and transported in compact stacks pending installation, said stairway components comprising a first vertical mast, a second vertical mast adapted to be fixed in spaced and aligned relationship to said first mast, a first stair supporting means fixed adjacent to the upper end of said first mast, a

second and third stair supporting means fixed in spaced relationship on said second mast so that said first stair supporting means is disposed in a horizontal plane between the horizontal planes of said second and third stair supporting means, said first, second and third stair supporting means each comprising horizontally disposed beam means connected solely intermediate the ends thereof to said first (or second masts, a first stair unit supported between said first and second stair supporting means on one side of said first and second masts, and a second stair unit supported between said first and third stair supporting means on the opposite side of said masts from said first stair unit.

2. The invention as defined in claim 1 wherein each of said first and second masts included a first vertical post and a second vertical post and wherein a third mast having with a third post including means coactable with means on said first vertical post for connecting said first and third posts in vertical alignment, said post having a fourth stair supporting means in the form of a horizontal beam connected intermediate the ends thereof to said third post, and a third stair unit supported between said third and fourth stair unit supporting means on the same side of said masts as said first stair unit.

3. The invention as defined in claim 2 wherein a fourth mast including a fourth past having means coacting with means on said second post for connecting said second and fourth mast in vertical alignment, said fourth mast having a fifth stair unit supporting means connected intermediate the ends thereof to said post, whereby a fourth stair unit may be supported between said fourth and fifth stair supporting means on the same side of said masts as said second stair unit supporting means and said fourth stair unit supporting means.

4. The invention as defined in claim 3 wherein said third and fourth masts are of identical structure.

5. The invention as defined in claim 4 wherein each of said stair units includes means at the upper and lower ends thereof for engaging said associated stair unit supporting means so that said stair units are restrained against lengthwise movement.

6. The invention as defined in claim 1 wherein said first and second coacting post means include aligning means and said third and fourth post coacting means includes opening means complementary to and for receiving said aligning means whereby said masts are aligned.

7. The invention as defined'in claim 6 wherein each of said post is of tubular structure and said aligning means comprises a block inserted one end of said post and said opening comprises a bore in said tubular post.

8. A knock-down stairway system having the components thereof designed and adapted to store and transport in compact stacked arrangement pending installation said components including a first mast and a second mast occupying spaced apart vertical positions of use, a first stair unit and a second stair unit, means for establishing said stair units in fixed relation to said masts at opposite sides of a vertical plane containing said masts and spanning the distance between said masts, said means including a first arm secured to said first mast to which said first and second stair units are joined at a common horizontal level, a second arm secured to said sec md m rst t w ic h said firs s air unit is oined m upwar ly me me re ation to san irst arm and a third arm secured to said second mast to which said second stair unit is joined in downwardly inclined relation to said first arm. 

1. A prefabricated stairway having the components thereof designed so as to be storable and transported in compact stacks pending installation, said stairway components comprising a first vertical mast, a second vertical mast adapted to be fixed in spaced and aligned relationship to said first mast, a first stair supporting means fixed adjacent to the upper end of said first mast, a second and third stair supporting means fixed in spaced relationship on said second mast so that said first stair supporting means is disposed in a horizontal plane between the horizontal planes of said second and third stair supporting means, said first, second and third stair supporting means each comprising horizontally disposed beam means connected solely intermediate the ends thereof to said first or second masts, a first stair unit supported between said first and second stair supporting means on one side of said first and second masts, and a second stair unit supported between said first and third stair supporting means on the opposite side of said masts from said first stair unit.
 2. The invention as defined in claim 1 wherein each of said first and second masts included a first vertical post and a second vertical post and wherein a third mast having with a third post including means coactable with means on said first vertical post for connecting said first and third posts in vertical alignment, said post having a fourth stair supporting means in the form of a horizontal beam connected intermediate the ends thereof to said third post, and a third stair unit supported between said third and fourth stair unit supporting means on the same side of said masts as said first stair unit.
 3. The invention as defined in claim 2 wherein a fourth mast including a fourth past having means coacting with means on said second post for connecting said second and fourth mast in vertical alignment, said fourth mast having a fifth stair unit supporting means connected intermediate the ends thereof to said post, whereby a fourth stair unit may be supported between said fourth and fifth stair supporting means on the same side of said masts as said second stair unit supporting means and said foUrth stair unit supporting means.
 4. The invention as defined in claim 3 wherein said third and fourth masts are of identical structure.
 5. The invention as defined in claim 4 wherein each of said stair units includes means at the upper and lower ends thereof for engaging said associated stair unit supporting means so that said stair units are restrained against lengthwise movement.
 6. The invention as defined in claim 1 wherein said first and second coacting post means include aligning means and said third and fourth post coacting means includes opening means complementary to and for receiving said aligning means whereby said masts are aligned.
 7. The invention as defined in claim 6 wherein each of said post is of tubular structure and said aligning means comprises a block inserted one end of said post and said opening comprises a bore in said tubular post.
 8. A knock-down stairway system having the components thereof designed and adapted to store and transport in compact stacked arrangement pending installation said components including a first mast and a second mast occupying spaced apart vertical positions of use, a first stair unit and a second stair unit, means for establishing said stair units in fixed relation to said masts at opposite sides of a vertical plane containing said masts and spanning the distance between said masts, said means including a first arm secured to said first mast to which said first and second stair units are joined at a common horizontal level, a second arm secured to said second mast to which said first stair unit is joined in upwardly inclined relation to said first arm and a third arm secured to said second mast to which said second stair unit is joined in downwardly inclined relation to said first arm. 